C# - Converting string into nullable Guid?

Question

Is there an easier way of converting a string into a Guid?? Just now I have this code:

if (Guid.TryParse(request.QueryStringParameters["key"], out Guid result))
{
    whateverFunction(result);
}
else
{
    whateverFunction(null);
}

I was hoping there would be an easier way such as casting to (Guid?) or doing new Guid?() however neither of them seem to work. This needs to happen a lot of times in my program, obviously I can just put it in a function and that would be fine but hoping there is a cleaner way of doing this.

Answer 1

Alternatively, you can write your code like this:

var nullableGuid = Guid.TryParse(request.QueryStringParameters["key"], out var result)
    ? result
    : (Guid?)null;

whateverFunction(nullableGuid);

Answer 2

Just write your own method:

public Guid? TryParseGuid(string input)
{
   if (Guid.TryParse(input, out Guid result))
   {
       return result;
   }
   else
   {
       return null;
   }
}

You can use it the following way:

whateverFunction(TryParseGuid(request.QueryStringParameters["key"]));